There are two ways for users to get the free currency, and both involve taking your extra loose change to a nearby CoinStar machine coin-counting machine. Just changing your coins for a cash voucher nets you 10 free Facebook Credits, but using those proceeds to buy Facebook Credits directly from Rixty gets you a bonus of up to seven percent of your purchase. That bonus maxes out at a $150 purchase (and 105 Facebook Credits) so don't even think about converting your entire savings account into Facebook Credits (via Rixty) and making a tidy 7% profit on the transaction, because we thought of it first and it won't work.